Method of plugging or packing off strata in wells



March 928.

H. M. RYDER ET AL METHOD OF PLUGGING OR PACKING OFF STRATA IN WELLSFiled Jan. 19 27 Patented .Mar. 6, 1928.-

UNITED STATES PATENT 1 OFFICE.

HARRY HOYER RYDER AND EBEON J. BAILEY, F BRADFORD, PENNSYLVANIA, AS-

SIGNORS TO PETROLEUM RECLAMATION CORPORATION,

CORPORATION OF DELAWARE.

or new Yonx, N. Y., A

METHOD or rmresme on racxmc our s'rnA'rA In 'wn'mzs.

Application filed January 19, 1927. Serial No. 161,998.

well wall, which irregular shape may be due to many causes, as forexample, cavlng,

shooting, etc. I

The general object of this invention isto provide an inexpensive,-reliable and efiective, method for sealing undesirable strata,

. regardless of the irregularity of the well wall, whereby such strataare rendered nonpermeable to water.

Other objectsand advantages of the Invention will become apparent fromthe 91- 26 lowing description, taken in connection wlth the accompanyingdrawing which is a diaammatic sectional view of a plurality of stratathrou h which a well has been drilled, one of whic strata is shown asplugged or packed ofi according to the herein described method.

Although the method embodying this invention may be employed inconnection with various types of wells, it will be described 85particularly in connection-with a water intake well 10, such as isordinarily employed in flooding processes for increasin 'oi recovery.The well 10 is illustrate as drilled from the surface of the ground toan oil bearing stratunr'of sand 11,.through. a

water bearing stratum 12, a porous stratum I 13 and other strata'14, 15and 16 of various kinds. The well 10"is shown equipped with the usualwell casing or tube 18, around I which are arranged suitable packers 19and 20 of well known forms adapted to prevent water from being lost inthe stratum, 15. The casing ortube18 is shown. provided with aplurality'of openings '23 and 24,.the

Q former of which open into the shot hole 22,

and the latter of. which open into the well 10 in thevicinity of thewater bearing stra:

turn 12 and at a point above the packer 19. The casing 18 is shownsurrounded at its top by the usual plug 26; and provided at a point justbelow the opening 24 with a suitableseat 27 of the type commonly knownas the McGregor seat.

In a well of the type herein shown, which is ordinarily used in floodingprocesses for increasing oil recovery, water is eithen supplied. from asuitable source above ground or is allowed to pass from the waterbearing stratum 12 into the well casing or tube 18, from which itescapes into the shot hole 22, from which it is forced, due tohydrostatic pressure within the well casing or tube 18, intothe oil'bearing stratum 11, I thereby forcing the oil along such stratum toother wells or pumping stations from 7 which the oil is recovered.

Should a well be so formed that communication is aflorded' between anoil bearing stratum and a porous stratum, which may or .may not belocated contiguous to the oil bearing stratum, a large portion of thewater employed in the above mentioned flooding process may be wasted byreason of its being absorbed in the porous stratum, thus rendering suchflooding process more or less ineflicient due to-the impracticability offurnishing a sufficient supply of water to the well to overcome theamount lost through the porous stratum. Such a porous stratum 13 isherein shown contiguous to the oil bearing stratum 11, so thatcommunication between these strata would be aflt'ordedthrough theirregularly 1 shaped .shot hole 22, if the stratum 13 were not sealed.The illustration shown in the 00 drawing furnishes a striking example ofa possible condition under which it would be practically impossible toseal oficommunication between the, oil bearing stratum 11 and the porousstrata- 13, by such packers of rubber or other material as haveheretofore been employed. However,'with the method embodying thisinvention, communication between the stratum 11 and the stratum 13 maybe, effectively closed. In carrying out this method, a pipe 25 isinserted into the well casing or tube 18 from the to thereof; thispipebeing provided at its ower end with a. packer 26, which is adaptedto nest upon the seat 27, thereby tem orarily preventing water from thewater earing stratum 12 from flowing down through the well casing ortube 18 below the seal afiorded between the seat 27 and the packer 26.With the water from the water bearing stratum 12 shut off from thatportion of the well f casing orv tube 18 below the seat 27, such wateras may remain within the well casing or tube 18 below the seat 27 drainsinto the strata 11 and 13 to a level, say in the plane of the bottom ofthe stratum 16. After the water level within the well casing or tube 18has thus dropped a suitable sealing material 28, having. a lowerspecific gravity than the waterwithin the shot hole 22, is introducedinto the pipe from any suitable source of supply. The sealing material28 passes through the pipe 25 and into the wellcasing or tube 18, fromwhich it passes through the openings 23 into the shot hole 22 containingwater. Since the sealing material 28 is lighter than the water confinedwithin the shot hole 22, such sealing material rises to the top thereofand displaces the water in the upper portion of the shot hole. In orderto facilitate movement of the sealing material down through the pipe 25and well casing or tube 18, when, for example, a natural head" of waterexists in the well and extends a suflicient distance above theoilbearing stratum 11 to interfere with the downward movement of thesealing material, the upper end of the pipe 25 may be closed, forexample by means of'a valve 30 and fluid pressure, such as air pressurefrom a suitable. source, not shown, may be placed in communication withthe pipe 25. through a suitable connection 32 which may be provided witha valve 33 adapted to be opened g and closed as-conditions may require.The

fluid pressure thus applied-to the top, of the column ofsealingmateria'l'28 serves to force the sealing material down throughthe pipe 25 and well casing or tube 18 and into the shot hole'22. Thesealing material 28 is pref :r-

ably such that it will penetrate the porous strata only to a slightextent, if at all, and is of such a nature that it will efiectiv'elyseal the cavity or space into which it is introduced.

A suitable sealing material may consists of i 85% of a wax distilledresidue, known at the refinery as black oil,"-and 15% of what is knownat the refinery as dark fueloil. the black oil congealing atj'atemperature of ap-' proximately F. This black oil is diluted with thefuel oil in order to obtain a blend of a consistency which will,flow'down the pipe '25 and well casing or tube 18 without necessitating theuse of excessive air pressure to facilitate such moyement.-. Inpractice, a sufiiclent quantity of sealing material 28 is employed tocompletely the cavity .to a

point, well below the lower plane of the porousstrata, as for example,in the form around said casing .of

of well shown in the drawing, to a plane coincidentwith the-lower planeof the stratum 16.

After having thus sealed'the porous stratum or strata, a sufiicientperiod, for example four or five days, is allowed to lapse beore water,pressure is introduced into the well casing or tube 18, which waterpressure may be applied by removing the pipe 25 thereby establishingcommunication between the water bearing stratum 12 and that portion ofthe well casing or tube 18 below the seat 27, or by connecting the upperend of the well casing 18 to a suitable source of water above ground.Such introduction of water, either from the stratum 12 or from a sourceabove ground, sets up a I pressure within the shot hole 22, with theresult that the sealing material 28 is further packed into the upper endof the shot hole 22 and the oil withinthe oil bearing stratum is drivenon toward the pumping wells.

If the stratum to be sealed or rendered non-permeable to water islocated below the oil bearing stratum, a suitable material heavierthanwater orthe solution ordinarily applied in flooding the oil bearingstratum, may .be employed, in which case the process may be carried outsubstantially as above described.

What is claimed is: Y

1. The method of plugging' the space around a well casing, whichconsists inintroducing into the well a sealing material in the presenceof a displaceable liquid which'has a specific gravity different fromthat of the sealing material, leaving said sealing material anddisplaceable liquid undisturbed until thesealing material moves intosealing'position owing to the different specific gravities of saidsealing .material and displaoeabl'e' material after 1t is in sealingposition.

2.- The method of plugging water pervious strata in wells, whichconsists in. introducing a sealing material into the well and floatingliquid, and applying pressure to thesealing the sealing material intosealing posit-ion, and applying pressure to the sealing mate:

rial after it is 1n sealing position. 3. The method of plugging waterperviou strata in a-well, which consists in introducing an oil intothewell and floating said oil into sealing position by a liquid having aspecific gravity greater than that of the oi and applymg pressure to theoil? I 4. The method of plugging the space around the casing of a wellcontaining liquid. which consists in introducing into the well casing asealing material havm a specific gravityless than the liquid wit 'n thewell, and applying pressure to" the sealing material to eject it fromsaid easing into the space around said casing.

5. The inethod of luggin a well i the space containing liquid, whichconsists in introducing into the well casing a sealing material havin aspecific gravity less than the liquid wit iin the well,and applyingpressure to the sealing material to e ect it from said easing into thespace around said casing whereby it will be buoyed into sealing positionby said liquid, and applying pressure to the sealing material after itis in sealing position. v

6. The method of sealing predetermined strata in 'wells used-for waterflooding in connection withoil and gas recovery, which consists inintroducing a sealing material into the well at a selected point, andfloating the sealin material into sealing position by as and oilrecovery, the

sisting in introducing a sealing material into the space affordedbetween the well casin and the wall of the well, and floating saidsealing material into sealing position at said selected point.

8. For use in wells used for flooding in connection with as and oilrecovery, the method of plugging the space around the well easing at aselected point with res ect to a predetermined stratum to be seale off,from' the gas and oil bearing stratum, consist-ing in introducing asealing material into the space afl'orded between the well casing andthe wall of the well, and floating said sealing material intosealingposition at said selected point, and applying pressure tosaid sealingmaterial after it has assumed sealing position.

signatures to this specification.

HARRY MOYER RYDER. LEON J, BAILEY.

In testimony whereof, we have aflixed our

